The present invention relates to a color ink-jet printer which is capable of high-speed, high-quality printing and has a low cost.
One known type of color ink-jet printer employs a rotary drum. In this printer, a plurality of print heads are arranged at prescribed intervals around the circumference, or arranged at prescribed intervals in the horizontal direction, of a carriage. An electrical signal is impressed on a piezoelectric transducer made of zircon lead titanate ceramic, barium titanate ceramic, etc., and ink in an ink chamber is discharged from a nozzle by the oscillation of an oscillating plate so that a dot is printed on a sheet of recording paper. Since the plurality of print heads are arranged at prescribed intervals, the information for a plurality of lines to be printed is stored beforehand as dot information in a delay memory. Suppose, for instance, that first and second print heads are separated by a distance of n bits from each other. When a dot printed on the printing paper by the first print head reaches the point of the second print head as the drum rotates, an ink droplet is jetted from the nozzle of the second print head so that it is superimposed over the first dot to print it. The delay time required during this operation corresponds to a delay memory of n bits. A colored picture can be printed by repeating this print operation by three print heads using different ink colors in sequence.
With the printing mechanism described above, however, it is difficult to print at high speed, because sequential scanning is used. In addition, a mechanical printing mechanism of this type has a rather complicated structure, and therefore the cost of the apparatus tends to be very high.
An object of the present invention is to provide a high-speed, high-quality, low-cost color ink-jet printer.
Another object of the present invention is to provide a very practical and inexpensive color ink-jet printer which can print quietly on ordinary paper, owing to its multinozzle printing mechanism.